A structural character recognition method according to a related art is usually used for online input. That is, stroke information of a character which is information detected by an electronic pen or touch is continuously and sequentially received and the structural features of the strokes are analyzed and modeled to recognize the information. Even when individuals have various note-taking habits, the structures of the strokes are uniform so that the above structural character recognition method is preferable.
In contrast, when the characters input from an image are recognized (OCR), a statistic recognition method using a neural network is mainly used. When a font is uniform or limited, the statistic recognition method has high recognition rate and is mainly used for text recognition using a scanner. However, in case of a character included in an external image of a natural environment having no specific font, the statistic recognition method is not suitable for a recognition method because it is hard to train various changes of fonts and thus the high recognition rate may not be expected.